The present invention relates to a process for preparing 9.alpha.-hydroxy-4-androstene-3,17-dione.
9.alpha.-hydroxy-4-androstene-3,17-dione has been known for a long time (J. Am. Chem. Soc. 80, 1958, 6148) and has an outstanding antiandrogenous and antiestrogenous effect. It is also a valuable intermediate product for preparing 4,9(11)-androstadiene-3,17-dione which, in turn, can be converted by conventional methods into numerous pharmacologically active steroids.
When microbiologically preparing this compound from 4-androstene-3,17-dione by the previously conventional methods, only relatively low yields of the desired product are obtained. (See, e.g., Biotechnology and Bioengineering, XI, 1969, 1183; and U.S. Pat. Nos. 3,080,298 and 3,116,200.)